Charts ....
That is why all cloud miners as far as I can see over sell their available hash power ... There is no way they could mine enough to cover all their costs and make a profit from it unless they over sell ... Does that make them a ponzi scheme ? Well, yes and no ... As far as I can see they are all at it, what it relies on is the company maintaining it's reputation and attractiveness to customers so they continually support it.
Many of the cloudmining farms are located in China where electricity is cheap. Hashnest announced 18.11.2014 that the electricity price has been lowered to CNY 0.6/kWh which is ~0.005$/kWh.